Seismic Risk Analysis of Concrete Gravity Dams under Near-Fault Ground Motions

2012 ◽  
Vol 256-259 ◽  
pp. 2240-2243
Author(s):  
Abdelhamid Hebbouche ◽  
Mahmoud Bensaibi ◽  
Hussein Mroueh
Keyword(s):  
Seismic Vulnerability ◽  
Human Life ◽  
Ground Motions ◽  
Probabilistic Method ◽  
Gravity Dams ◽  
Seismic Risk Analysis ◽  
Near Fault ◽  
Concrete Gravity Dams ◽  
Financial Losses

There are a large number of concrete dams worldwide. Some of the dams are in areas prone to seismicity and were built many years ago with minimal consideration to seismic loads. Dam safety during and after an earthquake, is the aim of the present study. The failure of a dam during an earthquake will be catastrophic in terms of human life and financial losses. In the present work, an analytical fragility analysis was performed in order to characterize the seismic vulnerability of concrete gravity dams by using a probabilistic method to model sources of uncertainty that could impact dam performance. The assessment of the seismic vulnerability of concrete gravity dams under near-fault ground motions was performed to assess their performance against seismic hazards. A case study was considered, it is about the dam of Oued el Fodda on the Oued Chelif River, West Algeria. This dam was designed in the early 1930s.

scholarly journals Evolution law of overall damage of concrete gravity dam under near-fault ground motion

2021 ◽  
Author(s):  
Yafei Zhai ◽  
Liaojun Zhang ◽  
Hanyun Zhang ◽  
Tianxiao Ma ◽  
Binghui Cui
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Gravity Dam ◽  
Gravity Dams ◽  
Near Fault ◽  
Concrete Gravity Dams ◽  
Fling Step ◽  
Ground Motion Records ◽  
Near Fault Ground Motion ◽  
Dynamic Damage

Abstract Strong earthquake cases of concrete gravity dams show that the foundation damage has an important influence on the seismic response and damage characteristics of the dam body. Compared with non-pulse ground motions, pulse-like near-fault ground motions have a wider response spectrum sensitive zone, which will cause more modes of the structure to respond, resulting in more serious damage to the structure. In order to study the real dynamic damage characteristics of concrete gravity dams under the action of near-fault ground motions, this paper takes Koyna gravity dam as the object and establishes a multi-coupling simulation model that can reasonably reflect the dynamic damage evolution process of dam concrete and foundation rock mass. A total of 12 near-fault ground motion records with three types of rupture directivity pulse, fling-step pulse and non-pulse are selected, deep research on the overall damage evolution law of concrete gravity dams. Considering the additional influence of different earthquake mechanisms, different site types and other factors on the study, the selected ground motion records are from the same seismic events (Chi-Chi), the same direction but different stations. The results show that the foundation of the concretes gravity dam often get damaged before the dam body under the action of strong earthquakes. Compared with the near-fault non-pulse ground motion, the structural damage of the gravity dam under the action of the near-fault directivity pulse ground motion is significantly increased, and causes greater damage and displacement response to the dam body. The near-fault fling-step pulse ground motion has the least impact on the dynamic response of the gravity dam structure.

scholarly journals Reliability analysis of built concrete dam

2019 ◽  
Vol 12 (3) ◽  
pp. 551-579
Author(s):  
K. O. PIRES ◽  
A. T. BECK ◽  
T. N. BITTENCOURT ◽  
M. M. FUTAI
Keyword(s):  
Structural Reliability ◽  
Failure Modes ◽  
Design Parameters ◽  
Concrete Gravity Dam ◽  
Gravity Dams ◽  
Deterministic Method ◽  
Concrete Dam ◽  
Case Study Analysis ◽  
Concrete Gravity Dams

Abstract The conventional design of concrete gravity dams still follows the deterministic method, which does not directly quantify the effect of uncertainties on the safety of the structure. The theory of structural reliability allows the quantification of safety of these structures, from the quantification of the inherent uncertainties in resistance and loading parameters. This article illustrates application of structural reliability theory to the case study analysis of a built concrete gravity dam. Results show that reliability of the built structure is greater than that of the designed structure. The study compares reliability for design conditions, with the corresponding safety coefficients, illustrating a lack of linearity between safety coefficients and reliability. Furthermore, the study shows which are the failure modes and the design parameters with greater influence on dam safety.

scholarly journals Determination of limit-states for near-fault seismic fragility assessment of concrete gravity dams

2018 ◽  
Vol 0 (0) ◽  
pp. 0-0 ◽  
Author(s):  
Mohammad Ali Sotoudeh ◽  
Mohsen Ghaemian ◽  
Abdolreza Sarvghad Moghadam
Keyword(s):  
Seismic Fragility ◽  
Gravity Dams ◽  
Limit States ◽  
Near Fault ◽  
Concrete Gravity Dams

scholarly journals Application of the Incremental Modal Analysis for Bridges (IMPAb) Subjected to Near-Fault Ground Motions

2020 ◽  
Author(s):  
Alessandro Vittorio Bergami ◽  
Gabriele Fiorentino ◽  
Davide Lavorato ◽  
Bruno Briseghella ◽  
Camillo Nuti
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Pushover Analysis ◽  
Vertical Component ◽  
Vertical Motion ◽  
Strong Motion ◽  
Seismic Action ◽  
Near Fault ◽  
Benchmark Solutions

Near-fault ground motions can cause severe damage to civil structures, including bridges. Safety assessment of these structures for near fault ground motion is usually performed through Non-Linear Dynamic Analyses, while faster methods are often used. IMPAb (Incremental Modal Pushover Analysis for Bridges) permits to investigate the seismic response of a bridge by considering the effects of higher modes, which are often relevant for bridges. In this work, IMPAb is applied to a bridge case study considering near-fault pulse-like ground motion records. The records were analyzed and selected from the European Strong Motion Database and the pulse parameters were evaluated. In the paper results from standard pushover procedures and IMPAb are compared with nonlinear Response-History Analysis (NRHA), considering also the vertical component of the motion, as benchmark solutions and incremental dynamic analysis (IDA). Results from the case study demonstrate that the vertical seismic action has a minor influence on the structural response of the bridge. Therefore IMPAb, which can be applied considering vertical motion, remains very effective conserving the original formulation of the procedure, and can be considered a well performing procedure also for near-fault events.

Seismic risk analysis of concrete moment-resisting frames against near-fault earthquakes

2020 ◽  
pp. 1748006X2094047
Author(s):  
Ehsan Khojastehfar ◽  
Farzad Mirzaei Aminian ◽  
Hamid Ghanbari
Keyword(s):  
Risk Analysis ◽  
Seismic Risk ◽  
Ground Motions ◽  
Seismic Risk Analysis ◽  
Strong Ground Motions ◽  
Near Fault ◽  
Moment Resisting Frames ◽  
Short Period ◽  
Moment Resisting ◽  
Strong Ground

Characteristics of earthquake strong ground motions play an important role in the calculation of seismic-induced risk imposed on the structures. Distinguished features exist in movements recorded near seismic sources, as a result of a substantial amount of energy in a short period of record arrival time. In this article, seismic risk analysis of concrete moment-resisting frames due to near-fault strong ground motion is calculated and compared with that of caused by far-field strong ground motions. To achieve this goal, three moment-resisting frames with 4, 6, and 10 stories were designed based on international seismic design code. These frames are modeled applying modified Ibarra–Krawinkler moment–rotation nonlinear model in which strength and stiffness deterioration are involved. Seismic risk analysis of the frames is implemented using the Pacific Earthquake Engineering Research Center approach. Through this approach, probabilistic seismic hazard, probabilistic structural demand, probabilistic structural damage, and probabilistic loss curves are combined. Mean annual frequency of exceedance of seismic-induced losses presents probabilistic seismic risk of the sampled frames. According to the achieved results, the four-story frame (representative of low-rise frames) is more prone to be affected by near-fault strong ground motions in view of calculated seismic-induced risks.

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